Larger Raw Pictures In Picasa?

For a first and quick view of my photos (Panasonic GH2) I use Panasonics PhotofunStudio. Silkypix Pro 5.0 is my editing software. I was quite satisfied, untill I had the audacity to open a RAW file in Picasa. I discovered that both Panasonic and Silkypix literally don't show the whole picture. About 3 to 4% from the edges (it is hard to be exact) have been cut off. In some RAW photos I find a little discoloration near the edges, but others are perfectly allright. Does Panasonic play safe for a good reason? Is it common practice? Are Canon and Nikon and others doing te same? I understood RAW really meant RAW, including all raw data. What is the technical story behind it?